A new study has revealed the abrupt, body-wide changes women experience at the start of menopause, but also revealed that certain therapies could help reduce this impact.
Israeli researchers have found that women experience what they describe as a “physiological cliff” before their last period, during which many of the body’s systems undergo changes in a sudden period of time, rather than gradually with age.
Many of these changes also point to an increased risk of disease.
Menopause occurs when menstruation stops for 12 months or more and usually occurs in women around age 52 in the United States, but the age can range from 45 to 55 or older.
However, experts also found that menopausal hormone therapy – previously called hormone replacement therapy – resulted in less drastic bodily changes to several body systems, while cautioning that these findings were observational and required further investigation.
The study was published in the journal Natural medicine on October 12.
Women face a “physiological cliff” at menopause
Researchers examined more than 300 million laboratory tests performed on more than a million women in the United States and Israel between 1999 and 2024.
Uri Alon, the study’s author and professor of molecular cell biology at the Weizmann Institute of Science in Rehovot, Israel, said: News week that they found “gradual changes starting about a decade before menopause on average and accelerating in the years before the last menstrual period, then a jump during the last period.”
They found that sex hormones began to change in women’s bodies long before their last period. Anti-Müllerian hormone – the hormone that plays a role in fetal sexual differentiation – and estradiol – a potent form of estrogen – had already begun to decline rapidly about 15 and 12 years ago, respectively.
During this time, follicle-stimulating hormone – a hormone that regulates the growth and maturation of eggs – appears to be increasing compared to about 14 years ago.
They also found that sudden changes occurred in several biological systems of the female body before their last period. For example, in the U.S. data set specifically and in 52 of the 90 tests, researchers identified notable and abrupt changes affecting sex hormones, bone health, liver and kidney function, blood chemistry, and blood fats.
“We can’t say for sure how quickly this happens, but it seems like it happens within a year of the last menstrual period,” he said.
Comparable changes were also not observed in male individuals. “When we apply the same approach to men’s data, they don’t have a head start,” he added. “They show progressive aging changes over decades. Women also show these progressive changes as well as the jump.”
The researchers said this indicates that menopause is more of a sudden, multisystem physiological change that occurs in the female body, rather than a part of normal aging.
What impact do these changes have on the body?
Alon said these sudden changes occur in body systems affected by estrogen.
For example, this includes “bone mineral density, which drops about half a standard deviation on average in the population, which can trigger bone loss or osteoporosis,” he said.
He added that by the age of 70, a quarter of women suffer from osteoporosis. He said this is notable because it means that what might have been “an insignificant fall” at age 50, “just brush it off and get back up,” can then “cause a hip fracture at age 70, leading to 20 percent mortality in one year and 50 percent disability. So we think this pandemic of bone fractures among older women is potentially preventable.”
He also said the liver is significantly affected by these changes, meaning women experience “increased liver damage tests and also risk of liver disease.”
Additionally, “there is an increase in risk factors for heart disease, lipids and triglycerides,” he said. “The positive side is an improvement in iron and hemoglobin markers and a reduction in anemia, and the reason for this is the cessation of menstrual bleeding.”
Reduced impact of hormone therapy
Researchers also found that women taking hormone therapy for menopause had reduced changes in several measures, particularly those related to bone, liver and kidney function.
The treatment works by replacing the hormones estrogen and progesterone in the body – both of which drop to low levels as menopause approaches – and thus calms the sudden change in hormone levels in the body. It can reduce menopausal symptoms including hot flashes, night sweats, sleep problems, anxiety, and low mood, among others.
However, Alon said this finding “is observational and based on a small minority of women taking (hormonal treatment for menopause) and should therefore be taken with a grain of salt.”
He said the treatment “cleared most of the bone cliff and much of the cardiac marker cliff, but because these are only observations, clinical trials are needed to prove this.”
Additionally, not all women are advised to undergo this therapy. Those who have a history of breast, ovarian or uterine cancer; a history of blood clots; untreated high blood pressure; liver disease; or those who are pregnant are generally not recommended to take it.
What the results mean for women
Alon said he hopes the findings “do not cause stress or fear of menopause” but rather “emphasize the need for exercise, nutrition and other healthy habits before the last menstrual period.”
“They also support seeing a doctor, especially if you have risk factors for bone, heart or liver disease,” he added.
He also said that menopausal hormone therapy “is now given to prevent symptoms, but future clinical trials may confirm whether (menopausal hormone therapy) before menopause can also be given for (disease) prevention.”
Reference
Pridham, G., Hayut, Y., Lavi-Shoseyov, N. et al. (2026) Population-scale reconstruction of menopausal dynamics reveals physiological cliff during the last menstrual period. Natural medicine. https://doi.org/10.1038/s41591-026-04614-0
Contact Newsweek editors about this story: Marc Vargas And Paul Donnelley.
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